Obesity is a risk factor for a number of adverse psychosocial and medical outcomes. The prevalence of obesity in America has increased dramatically in recently years. Comprehensive cognitive-behavior (CBT) programs for obesity reliably produce medically significant weight reductions, but weight regain typically begins soon after weight loss ends. Improving the durability of initial weight losses is key to reducing the psychological and medical morbidity associated with obesity. This application proposes that weight loss maintenance could be improved by enhancing the nutritional component of CBT programs in two ways. First, since research shows that overweight individuals substantially under-report their food intake, interventions are needed to improve the accuracy of self-monitoring. As Enhanced Food Monitoring Accuracy (EFMA) intervention is proposed to improve self-monitoring and awareness of all food intake. Second, since lost-lasting changes in the nutritional composition of the diet are critical to weight loss maintenance, an Enhanced Nutritional Modification (ENM) intervention is proposed to facilitate sustained changes in nutritional intake during maintenance. Subjects will be 144 overweight Caucasian and African-American women. All participants will receive a standard CBT program and undergo 8 weeks of weight loss followed by 14 weeks devoted to weight maintenance. Subjects will be assigned at random to a CBT-only condition, a CBT+EFMA condition, or a CBT+EFMA+ENM condition. The EFMA intervention will focus on overcoming technical and psychological obstacles to accurate self-monitoring. The ENM intervention will significantly add to the breadth and depth of nutritional interventions employed in CBT programs. Dependent measures will include weight loss and maintenance, accuracy of food intake reporting, caloric and macronutrient intake, quality of life, nutritional knowledge and adherence, blood lipids, and blood pressure. Data will be collected at pretreatment, posttreatment, and at 6- and 18-month follow-ups.